Oral delivery of medications is one of the most frequent techniques utilized for delivering medication to the body. One of the most popular delivery mechanisms is the capsule. The background of U.S. Pat. No. 8,361,497 issued to Miller provides a detailed description into the history and present techniques for capsule manufacture and is hereby incorporated by reference.
Capsules containing medication for oral intake are usually swallowed for delivery of the medication to the stomach, where the capsule dissolves within 20 to 30 minutes and the medication is absorbed into the bloodstream.
A two piece capsule design is typically used for delivering medication in a solid form such as a fine powder or pellets. One or both portions of this capsule design are made of a material which quickly becomes mollified when coming in contact with liquid, such as water or gastric juice.
Nitroglycerin is a unique medication, one of the best and most efficient medications in the medical arsenal for the last 100 years. Nitroglycerin works therapeutically within one to two minutes to relieve angina and it is most specific for this life threatening condition. It is specifically used in treatment of the episodes of coronary insufficiency and angina, acute episodes, as well as for prevention of their recurrence. It is so specific, that if nitroglycerin does not effectively treat chest pain within a few minutes, the chest pain is either non-cardiac altogether, or manifests an acute coronary event, requiring immediate hospitalization.
Soft tablets containing nitroglycerin have also been developed for sublingual use and having rapid absorption into the blood stream. However, soft tablets are only effective when the patient does not have a dry mouth condition. Insufficient saliva in the mouth can be caused by Shogren's syndrome, calculi in salivary glands, dentures, the taking of certain medications such as Clonidine, breathing thru the mouth, or general dehydration. Any of these conditions can result in nitroglycerin not being absorbed as quickly as needed and which could lead to chest pain requiring immediate hospitalization. Further, nitroglycerin in tablet form is more often associated with severe headaches and syncope.
To avoid problems associated with use of nitroglycerin in a soft tablet form for sublingual use, nitroglycerin lingual spray was introduced as an efficient alternative.
Nitroglycerin lingual spray is effective and most commonly used outside of a hospital environment for self-administration. Typically, self-administration is via a multi-dose pump-spray container, filled with enough nitroglycerin for up to 200 doses in one container. Pump spray containers are not designed to regulate the number of doses a patient can self-administer in a short period of time and therefore the risk of an overdose is present most common when the patient is in panic due to pain and discomfort and in response administers more than the maximally allowed single volume/dose. This can lead to severe hypotension or syncope. Other problems with lingual spray include:
a) the pumpspray dose per spray may reduce as the quantity within the container is emptied. This can result in unpredictable or inadequate volumes of medication per spray dose being delivered which in turn can compel the patient to increase the doses resulting in overmedication frequently provoked hypotension and syncope.
b) the pumpspray is applied lingually rather than sublingually because a pump-spray is a bottle held between the index finger and the thumb of the user, positioned parallel to the curled up tongue. It is almost impossible to push the hand with the pump-spray into the mouth and orient the direction of the spray.
c) personal hygiene. The lingual pumpspray may routinely be used among different patients in a hospital setting (emergency room or cath lab), one or more out of the patients may cough or sneeze at the time of use, and transfer droplets of saliva and potential infection with it, from patient to patient;
d) the cost of a pumpspray can be expensive vs the price of a single dose. An individual may buy a pump-spray, containing 60 or 200 doses, and use the pumpspray only occasionally.
Another delivery method is capsular delivery wherein liquid medication such as nitroglycerin is swallowed and absorbed in the gastro-intestinal tract. While eventually being delivered into the bloodstream, this method is not as effective for acute conditions since absorption takes much longer than lingual or sublingual administration.